More important than the further improvement of romantic love is the task of increasing the proportion of men and women who will be capable of experiencing it as now known to us.  The vast majority are still strangers to anything beyond primitive love.  The analysis made in the present volume will enable all persons who fancy themselves in love to see whether their passion is merely self-love in a roundabout way or true romantic affection for another.  They can see whether it is mere selfish liking, attachment, or fondness, or else unselfish affection.  If adoration, purity, sympathy, and the altruistic impulses of gallantry and self-sacrifice are lacking, they can be cultivated by deliberate exercise: 

     Assume a virtue, if you have it not. 
     That monster, custom, who all sense doth eat,
     Of habits devil, is angel yet in this.

The affections can be trained as well as the muscles; and thus the lesson taught in this book may help to bring about a new era of unselfish devotion and true love.  No man, surely, can read the foregoing disclosures regarding man’s primitive coarseness and heartlessness without feeling ashamed for his sex and resolving to be an unselfish lover and husband to the end of his life.

A great mistake was made by the Greeks when they distinguished celestial from earthly love.  The distinction itself was all right, but their application of it was all wrong.  Had they known romantic love as we know it, they could not have made the grievous blunder of calling the love between men and women worldly, reserving the word celestial for the friendship between men.  Equally mistaken were those mediaeval sages who taught that the celestial sexual virtues are celibacy and virginity—­a doctrine which, if adopted, would involve the suicide of the human race, and thus stands self-condemned.  No, celestial love is not asceticism; it is altruism.  Romantic love is celestial, for it is altruistic, yet it does not preach contempt of the body, and its goal is marriage, the chief pillar of civilization.  The admiration of a beautiful, well-rounded, healthy body is as legitimate and laudable an ingredient of romantic love as the admiration of that mental beauty which distinguishes it from sensual love.  It is not only that the lovers themselves are entitled to partners with healthy, attractive bodies; it is a duty they owe to the next generation not to marry anyone who is likely to transmit bodily or mental infirmities to the next generation.  It is quite as reprehensible to marry for spiritual reasons alone as to be guided only by physical charms.

Love is nature’s radical remedy for disease, whereas marriage, as practised in the past, and too often in the present, is little more than a legalized crime.  “One of the last things that occur to a marrying couple is whether they are fit to be represented in posterity,” writes Dr. Harry Campbell (Lancet, 1898).